Shear panel building material

ABSTRACT

A shear panel building material that includes a first facing membrane, a core matrix disposed on a face of the first facing membrane, and a semi-rigid or rigid material attached to the core matrix. The core matrix can include microspheres having a size of about 200 microns to about 800 microns, sodium silicate, and ethylene vinyl acetate. In one aspect, the shear panel is substantially free from glue and cement.

RELATED APPLICATIONS

This application is a continuation application of U.S. patentapplication Ser. No. 13/176,692, filed Jul. 5, 2011, which is acontinuation of U.S. patent application Ser. No. 12/238,379, filed onSep. 25, 2008, which is a continuation-in-part of U.S. patentapplication Ser. No. 12/077,951, filed on Mar. 21, 2008, which claimsthe benefit of U.S. Provisional Patent Application No. 60/919,509, filedon Mar. 21, 2007, and of U.S. Provisional Patent Application No.60/961,130, filed on Jul. 17, 2007, and of U.S. Provisional PatentApplication No. 61/002,367, filed on Nov. 7, 2007, and U.S. ProvisionalPatent Application No. 61/081,951, filed on Jul. 18, 2008, all of whichare each incorporated by reference herein in their entireties.

FIELD OF THE INVENTION

The present invention relates generally to building materials, and moreparticularly to shear panels or shear-type building materials.Accordingly, the present invention involves the fields of chemistry,chemical engineering, manufacturing engineering, construction, andmaterials science.

BACKGROUND OF THE INVENTION AND RELATED ART

Shear panels, as they are generically known as, are common in thebuilding industry, and are used primarily to construct shear walls.Common types of shear panels are constructed from wood, metal orconcrete. There are several types of shear panels. One particular typeof shear panel used more frequently than others, particularly inresidential construction, is oriented strand board or OSB, which is anengineered wood product formed by layering strands (flakes) of wood inspecific orientations. Other types of shear panels include fiberboard,particle board, hardboard, masonite, plywood, just to name a few.

Several problems exist with these conventional types of shear panels.For example, they are poor sound attenuators, or rather they exhibitpoor noise reduction properties. Stated differently, they transmit orpass through a large percentage of the sound they are exposed to. Thus,when used to form exterior wall or flooring partitions, it is oftennecessary to equip the wall with insulation or other types of soundabsorbing materials to improve the Sound Transmission Class (STC) ratingacross the created partition.

STC, part of ASTM International Classification E413 and E90, is a widelyused standard for rating how well a building material attenuatesairborne sound. The STC number is derived from sound attenuation valuestested at sixteen standard frequencies from 125 Hz to 4000 Hz. Thesetransmission-loss values are then plotted on a sound pressure levelgraph and the resulting curve is compared to a standard referencecontour. Acoustical engineers fit these values to the appropriate TLCurve (or Transmission Loss) to determine an STC rating. STC can bethought of as the decibel reduction in noise that a wall or otherpartition can provide. The dB scale is logarithmic, with the human earperceiving a 10 dB reduction in sound as roughly halving the volume.Therefore, any reduction in dB is significant. The reduction in dB forthe same material depends upon the frequency of the sound transmission.

Another problem with conventional shear panels is that, by themselves,they have poor thermal insulating properties. They are typicallycombined with insulation or other heat resistant materials to provide aresulting walled partition with the needed resistance to heat transferor heat loss. This significantly increases costs of building asadditional materials and labor is required, while only providing minimumprotection.

SUMMARY OF THE INVENTION

In light of the problems and deficiencies inherent in the prior art, thepresent invention seeks to overcome these by providing a shear panelbuilding material including a microparticle-based core matrix, and arigid material that imparts added strength and other characteristics tothe shear panel building material.

In one aspect, a shear panel building material includes a first facingmembrane, a core matrix disposed on a face of the first facing membrane,and a semi-rigid or rigid material attached to the core matrix. The corematrix can include microspheres having a size of about 200 microns toabout 800 microns, sodium silicate, and ethylene vinyl acetate. In oneaspect, the shear panel is substantially free from glue and cement.

There has thus been outlined, rather broadly, various features of theinvention so that the detailed description thereof that follows may bebetter understood, and so that the present contribution to the art maybe better appreciated. Other features of the present invention willbecome clearer from the following detailed description of the invention,taken with the accompanying claims, or may be learned by the practice ofthe invention.

BRIEF DESCRIPTION OF THE DRAWINGS

The present invention will become more fully apparent from the followingdescription and appended claims, taken in conjunction with theaccompanying drawings. Understanding that these drawings merely depictexemplary embodiments of the present invention they are, therefore, notto be considered limiting of its scope. It will be readily appreciatedthat the components of the present invention, as generally described andillustrated in the figures herein, could be arranged and designed in awide variety of different configurations. Nonetheless, the inventionwill be described and explained with additional specificity and detailthrough the use of the accompanying drawings in which:

FIG. 1 illustrates a perspective view of a shear panel building materialin accordance with one exemplary embodiment of the present invention;

FIG. 2 illustrates a detailed partial perspective view of the shearpanel building material;

FIG. 3 illustrates a detailed partial perspective view of a shear panelbuilding material in accordance with another exemplary embodiment of thepresent invention;

FIG. 4 illustrates a perspective view of a shear panel building materialjust prior to being installed or mounted onto a stud wall;

FIG. 5-A illustrates a detailed partial end view of a shear panelbuilding material having a coupling system formed therein in accordancewith one exemplary embodiment of the present invention;

FIG. 5-B illustrates a detailed partial end view of a shear panelbuilding material having a coupling system formed therein in accordancewith another exemplary embodiment of the present invention;

FIG. 6 illustrates a detailed partial perspective view of a shear panelbuilding material in accordance with another exemplary embodiment of thepresent invention;

FIG. 7 illustrates a detailed partial perspective view of a shear panelbuilding material in accordance with another exemplary embodiment of thepresent invention

FIG. 8 illustrates a building material configured for use as a finishingmaterial on an exterior of a structure;

FIG. 9 illustrates a perspective view of a wood mold of for a bottompiece of a porous mold, in accordance with one aspect of the presentinvention; and

FIG. 10 illustrates a top view of a backing paper template, inaccordance with one aspect of the present invention.

DETAILED DESCRIPTION OF EXEMPLARY EMBODIMENTS

The following detailed description of exemplary embodiments of theinvention makes reference to the accompanying drawings, which form apart hereof and in which are shown, by way of illustration, exemplaryembodiments in which the invention may be practiced. While theseexemplary embodiments are described in sufficient detail to enable thoseskilled in the art to practice the invention, it should be understoodthat other embodiments may be realized and that various changes to theinvention may be made without departing from the spirit and scope of thepresent invention. Thus, the following more detailed description of theembodiments of the present invention is not intended to limit the scopeof the invention, as claimed, but is presented for purposes ofillustration only and not limitation to describe the features andcharacteristics of the present invention, to set forth the best mode ofoperation of the invention, and to sufficiently enable one skilled inthe art to practice the invention. Accordingly, the scope of the presentinvention is to be defined solely by the appended claims.

The following detailed description and exemplary embodiments of theinvention will be best understood by reference to the accompanyingdrawings, wherein the elements and features of the invention aredesignated by numerals throughout.

The present invention describes a shear panel building materialconfigured for use in constructing various structures, such as a shearwall, flooring, etc., similar to prior related shear panel materials.The shear panel building material helps to counter the effects oflateral and other loads acting on the structure. However, the presentinvention shear panel building material is also capable of beingutilized in other non-traditional applications, such as applicationsspecifically directed at attenuating or deadening sound, applicationsdirected at insulating a structure, etc.

The shear panel building material comprises a core matrix disposedbetween opposing facing membranes or layers, at least one of whichcomprises a rigid material, namely metal. The other facing membrane maycomprise a rigid material (e.g., metal or fiberglass) or a flexiblematerial, such as the type of paper common on conventional drywall-typewallboard products, etc. The composition of the core matrix comprises aplurality of hollow, inert, lightweight naturally occurring or syntheticmicrospheres that are substantially spherical in geometry (hereinafter“microspheres”), as well as at least one binder configured to adhere orbind the microspheres together, and to form a plurality of voids presentthroughout the core matrix. The binder may comprise an inorganic bindersolution, an organic or latex binder solution, or both of these incombination. The core matrix may also comprise various additives,fillers, reinforcement materials, etc. Each of the components of thepresent invention shear panel building material, as well as otherfeatures and systems, are described in greater detail below.Alternatively, the core matrix can be free from various additives and/orfillers and/or setting agents and/or reinforcement materials. In oneaspect, the core matrix can be free from fibrous materials. In anotheraspect, the core matrix can be free from cementing agents, such asvarious forms of cement. In a further embodiment, the core matrix can befree from lime.

The present invention further describes a method for manufacturing ashear panel building material. The shear panel may be manufactured inaccordance with the compositions and methods described in copending U.S.Application No. ______, filed Sep. 25, 2008, and entitled, “WallboardMaterials Incorporating a Microparticle Matrix” (Attorney Docket No.2600-32683.NP.CIP2), which is incorporated by reference in its entiretyherein.

In one aspect, the binder used in shear panel building material maycomprise an inorganic binder solution, an organic or latex bindersolution, or both of these in combination. The core matrix may alsocomprise various additives, fillers, reinforcement materials, etc.Alternatively, the core matrix can be free from one or more ofadditives, fillers, cements, and/or additional reinforcement materials.Each of the components of the present invention shear panel buildingmaterial, as well as other features and systems, are described ingreater detail below.

The present invention provides several significant advantages over priorrelated shear panel products, particularly Oriented Strand Board (OSB),particle board, etc., some of which are recited here and throughout thefollowing more detailed description. First, the present invention shearpanel building material provides enhanced thermal properties. Forexample, the present invention shear panel building material provides amuch greater resistance to thermal heat transfer due to the compositionof the core matrix. Second, the present invention shear panel buildingmaterial provides enhanced acoustical properties. For example, thepresent invention shear panel building material provides a significantlybetter Sound Transmission Class (STC) rating. Third, the presentinvention shear panel building material is stronger and lighter. Theproperties of the present invention shear panel are similar to those ofa wallboard building material having a similar core matrix, only thepresent invention shear panel building material is stronger, morewaterproof/resistant, and more fire resistant.

Each of the above-recited advantages will be apparent in light of thedetailed description set forth below, with reference to the accompanyingdrawings. These advantages are not meant to be limiting in any way.Indeed, one skilled in the art will appreciate that other advantages maybe realized, other than those specifically recited herein, uponpracticing the present invention.

In one aspect, the components of the core matrix may be modified toadjust the properties of the shear panel building material. For example,the core matrix composition may be configured to provide enhancedthermal insulation, fire resistance, acoustical insulation, moldretardant and/or other desirable properties. The shear panel buildingmaterials can provide enhanced filtering abilities. By varying thenumber, size, composition, and/or shape of microparticles, the bindermaterial, the ratio of microparticles to binder and other optionalcomponents (e.g., surfactant), the processing steps and parameters, andother variables, the properties of the shear panel building material canbe modified to desired functionality.

In general, the shear panel building materials of the present inventioncomprise a plurality of microparticles that are at least bound oradhered together, and preferably bonded together, by one or more bindersto create a core matrix structure having a plurality of voids definedtherein. Depending upon the selected composition, the shear panel may beconfigured to exhibit certain physical and performance properties, suchas strength, flexibility, hardness, as well as thermal and/or acousticalproperties, fire and/or mold resistant properties, etc.

Each of the above-recited advantages will be apparent in light of thedetailed description set forth below, with reference to the accompanyingdrawings. These advantages are not meant to be limiting in any way.Indeed, one skilled in the art will appreciate that other advantages maybe realized, other than those specifically recited herein, uponpracticing the present invention.

In describing and claiming the present invention, the followingterminology will be used in accordance with the definitions set forthbelow. The singular forms “a,” “an,” and, “the” include plural referentsunless the context clearly dictates otherwise. Thus, for example,reference to “a wallboard” includes reference to one or more of suchwallboards, and reference to “the binder” includes reference to one ormore of such binders.

As used herein, “substantially” refers to situations close to andincluding 100%. Substantially is used to indicate that, though 100% isdesirable, a small deviation therefrom is acceptable. For example,substantially free of mold includes situations completely devoid ofmold, as well as situations wherein a negligible amount of mold ispresent, as determined by the particular situation.

As used herein, the term “about” is used to provide flexibility to anumerical range endpoint by providing that a given value may be “alittle above” or “a little below” the endpoint.

For purposes of discussion and interpretation of the claims as set forthherein, the term “building material,” as used herein, shall beunderstood to mean various types of products or materials incorporatinga matrix of microparticles (e.g., microspheres) adhered or boundtogether using one or more components, such as a binder of some kind,and specifically means shear panel building materials. The buildingmaterials may comprise other additives, components or constituents, suchas setting agents, foaming agents or surfactants, water solublepolymers, and others. The building materials may comprise many differenttypes, embodiments, etc., and may be used in many differentapplications.

The term “microparticle,” as used herein, shall be understood to meanany naturally occurring, manufactured, or synthetic particle having anouter surface, and in some cases, a hollow interior. Generally, themicroparticles referred to herein comprise a spherical or substantiallyspherical geometry having a hollow interior, known as microspheres.Other types of microparticles may include those made from wood, groundrubber, ground up plastic, sawdust, etc.

The term “core matrix,” as used herein, shall be understood to mean thecombination of microparticles and other constituents used to form thesupport matrix of the building materials. The microparticles may becombined with one or more binders, additives, setting agents, etc.

The term “multi-elevational” shall be understood to describe at leastone surface of the core matrix of the building material, wherein thesurface has formed therein a series of peaks and valleys (or protrusionsand recesses) to provide an overall surface configuration havingdifferent surfaces located in different elevations and/or orientations.The multi-elevational surface configuration may be arbitrarily formed orpatterned. In addition, the multi-elevational surface may be defined byany arbitrary or geometrically shaped protruding and recessedcomponents.

As used herein, a plurality of items, structural elements, compositionalelements, and/or materials may be presented in a common list forconvenience. However, these lists should be construed as though eachmember of the list is individually identified as a separate and uniquemember. Thus, no individual member of such list should be construed as ade facto equivalent of any other member of the same list solely based ontheir presentation in a common group without indications to thecontrary.

Concentrations, amounts, and other numerical data may be expressed orpresented herein in a range format. It is to be understood that such arange format is used merely for convenience and brevity and thus shouldbe interpreted flexibly to include not only the numerical valuesexplicitly recited as the limits of the range, but also to include allthe individual numerical values or sub-ranges encompassed within thatrange as if each numerical value and sub-range is explicitly recited. Asan illustration, a numerical range of “about 1 to about 5” should beinterpreted to include not only the explicitly recited values of about 1to about 5, but also include individual values and sub-ranges within theindicated range. Thus, included in this numerical range are individualvalues such as 2, 3, and 4 and sub-ranges such as from 1-3, from 2-4,and from 3-5, etc.

This same principle applies to ranges reciting only one numerical value.Furthermore, such an interpretation should apply regardless of thebreadth of the range or the characteristics being described.

With reference to FIGS. 1 and 2, illustrated are a general perspectiveview and a detailed perspective view, respectively, of a shear panelbuilding material in accordance with one exemplary embodiment of thepresent invention. As shown, the shear panel building material 10 is inpanel form having a size of approximately 4 ft. in width, and 8 ft. inlength, and approximately ½ inch thick, which is the same size as mostconventional shear panel products. Of course, other sizes such 4 ft. by12 ft. sizes, as well as different thicknesses is also contemplated. Theshear panel building material 10 is shown as comprising a core matrix 14disposed between opposing facing membranes or layers, namely firstfacing membrane 34 and second facing membrane 54. The shear panelbuilding material 10 is also shown as comprising a reinforcing member 74disposed within the core matrix, also between the first and secondfacing membranes 34 and 54.

The core matrix 14 is comprised primarily of a plurality of microspheresand at least one binder, wherein the microspheres are at least bound oradhered together, and preferably bonded together, by the one or morebinders to create a core matrix structure having a plurality of voidsdefined therein. The voids are formed from the point to point contactbetween the microspheres.

The microparticles contemplated for use herein may comprise manydifferent types, sizes, shapes, constituents, etc. Although not limitedto this, the microparticles used in the present invention buildingmaterial will generally have a size ranging between about 10 and about1500 microns, or between about 10 and 1000 microns, and preferablybetween about 200 and about 800 microns. In a specific embodiment, themicroparticles have a size ranging from about 300 to about 600 microns.In another aspect, the microparticles can have an average mean particlesize of about 350 microns to about 450 microns. The microspheres ormicroparticles can optionally have a bulk density of about 0.4 to about0.6 g/ml, providing products that are much lighter than conventionalbuilding materials, such as oriented strand board (OSB). The size of themicroparticles will depend upon the application and the performancecharacteristics desired. However, the particles should not be too largeso as to cause any binder disposed thereon to run off or to not beeffective. The size of the microparticles will also function toinfluence the permeability of the building material. The microparticlesare intended to be compatible with any binders, additives, and/or facingsheets. The shell thickness of the microparticles may be kept to aminimum amount, provided the microparticles maintain structuralintegrity as desired in the core matrix material. In one aspect, themicroparticles can have a shell thickness of less than about 30% of thediameter of the microparticle. Wherein the microparticles are notspherical, the diameter of the particle can be calculated based on theeffective diameter of the particle, using the total area of the crosssection of the particle and equating such area to a circumferential areaand determining the diameter from that value. In a further embodiment,the shell thickness can be less than about 20% of the diameter of themicroparticle.

In one exemplary embodiment, the microparticles may comprise hollow,inert, lightweight naturally occurring, glass particles that aresubstantially spherical in geometry, or shaped as microspheres. Oneparticular type of microsphere is sold under the trademarkExtendospheres™, which are manufactured and sold by Sphere OneCorporation. A hollow interior is preferred as this will reduce theweight of the shear panel building material, as well as provide goodinsulating properties. Furthermore, in one aspect, the microspheres ormicroparticles maintain structural integrity and retain their hollownature, or original formation to the exclusion of binder or other matrixmaterials infiltrating the hollow portions of the microspheres. In oneaspect of this embodiment, the microspheres may comprise the naturallyoccurring hollow, inert, glass microspheres obtained from a fly ashbyproduct, which microspheres are often referred to as cenospheres.These cenospheres may be separated from the other byproduct componentspresent in the fly ash and further processed, such as to clean andseparate these into desired size ranges. Cenospheres are comprisedprimarily of silica and alumina, and have a hollow interior that isfilled with air and/or other gasses. They possess many desirableproperties, such as a crush strength between 3000 and 5000 psi, lowspecific gravity and are able to endure extremely high temperatures(above 1800° F.). Although they are substantially spherical in overallshape, many are not true spheres, as many are fragmented, or compriseunsmooth surfaces caused by additional silica and/or alumina.

As noted, microparticles or microspheres can include an amount of air orother gasses within the hollow interior. Where possible, the compositionof the gaseous material within the microsphere can optionally beselected so as to provide enhanced characteristics of the utilitymaterial. For example, the hollow interior can include a noble gas, suchas argon, or other known insulating gasses, to improve the insulatingproperties of the overall utility material.

In another exemplary embodiment, the microspheres may compriseartificial hollow, spherical structures manufactured from a syntheticmaterial. The advantage with having a synthetic material is theuniformity and consistency between microspheres, thus making theirbehavior and the behavior of the resulting core matrix and buildingmaterial more predictable. However, these advantages may not besignificant enough to justify their use, as synthetic microspheres areextremely expensive to manufacture and can be cost prohibitive in manyapplications. The use of naturally occurring microspheres over syntheticones to form a building material may depend on several differentfactors, such as the intended application, and/or the desiredperformance properties or characteristics. In some applications,naturally occurring microspheres may be preferred while in others asynthetic type may be more desirable. In one aspect, however, acombination of naturally occurring microspheres and syntheticmicrospheres can be utilized together in the core matrix. Thecombination of microspheres can be a homogeneous or heterogeneousdistribution throughout the utility material.

In one aspect, microspheres may be present in an amount between 25 and60 percent by weight of the total core matrix, in wet mixture form.Preferably, the microspheres are present in an amount between about 30and 40 percent by weight. Other amounts are further contemplated in theevent other additives or fillers, such as perlite, or setting agents,such as Class C fly ash, are made part of the core matrix composition.It should be noted that fly ash, of any type, can be utilized as afiller material, and/or optionally as a source of cenospheres. In oneaspect, Class C fly ash can be one or the only source of microspheres.Class C fly ash can, in one aspect, be included in a core matrix in anamount ranging from about 0.5 wt % to about 50 wt %. In one aspect, itcan be present in combination with synthetically made microspheres at aratio of Class C fly ash to synthetic microspheres of about 1:15 toabout 15:1. In a further embodiment, Class C fly ash can be present inan amount of less than about ⅓ of the amount of microspheres. The ClassC fly ash used can optionally include greater than about 80 wt % calciumaluminum silicates, and less than 2 wt % lime.

The present invention further comprises one or more binders operable tocouple together the microspheres, and to facilitate formation of theporous core matrix. The microparticles or microspheres can be bound byany manner, including a physical cementing arrangement, chemicallybinding microspheres, merging boundaries of microspheres, etc. In aspecific embodiment, the microspheres can be bound by a physicalcementing arrangement, as held together in a matrix of binder, whereinthe binder adheres or physically immobilizes the microspheres, but doesnot form covalent or other chemical bonding with the microspheres. Thebinder may be caused to adhere the microspheres together, wherein thebinder is allowed to dry if water based, or cured in a high temperatureenvironment if non-water based. In another aspect, the binder may becaused to be cross-linked, wherein the binder functions to bond themicrospheres together to improve the water resistant properties of thebuilding material.

The ratio of binder to microparticles may vary depending upon the shearpanel building material to be formed. A higher ratio of binder tomicroparticles will result in a shear panel building material that ismore solid and dense than one with a smaller ratio. Indeed, a smallerratio of binder to microparticles will result in a more porous shearpanel.

The present invention contemplates the use of many different types ofbinders, again depending upon the desired type of shear panel buildingmaterial to be formed. Different binders may be selected as part of thecomposition to contribute to the makeup of the resulting shear panelbuilding material and to help provide the shear panel building materialwith certain physical and performance properties.

Both water-based and non-water-based binders are contemplated for use.Any one of these may be used alone or in combination with anotherbinder. Examples of general binder categories include, but are notlimited to, thermoplastics, epoxy resins, curatives, urethanes,thermosets, silicones, and others.

In one exemplary embodiment, the binder comprises an inorganic binder,such as sodium silicates in one form or another, combined with anorganic binder such as polyvinyl acetate copolymer or ethylene vinylacetate. The ratio of these binders may vary. In one aspect, the ratioof inorganic binder to organic binder may be about 7:1 to about 10:1.Stated more generally, the inorganic binder may be present in an amountbetween 50 and 60 percent by weight of the total weight of the corematrix (or about 20 to about 36 wt % dry inorganic binder), in wet form(the binders comprise an amount of water, or are mixed with an amount ofwater), with the organic binder present in an amount between 5 and 15percent by weight of the total weight of the core matrix, in wet form(or about 2 to about 6 wt % dry organic binder). The listed amounts canbe based on the pure forms of the binder material (with the percentweight of the binders in the total core matrix discussed herein beingreduced between 40 and 60 percent), e.g. on pure sodium silicate, or canbe based on binder mixtures including optionally water, similar chemicalforms, e.g. silicates, silicic acid salts, etc., and other additives. Asa non-limiting example, a sodium silicate binder solution commerciallysold includes from about 35 wt % to 40 wt % sodium silicate in solution.Furthermore, more than one type of inorganic and/or organic binder canbe utilized simultaneously.

In a specific embodiment, the core matrix composition can containbetween 400 g and 600 g of microspheres, mixed with between 600 g and800 g of sodium silicate binder solution, and between 60 g and 100 g ofethylene vinyl acetate. Of course, other ranges are possible, dependingupon the application. For example, it may be desirable to have between200 g and 1500 g of sodium silicate or other binder mixed with between300 and 800 g of microspheres, mixed with between 20 g and 180 g ofethylene vinyl acetate copolymer. Other ratios and ranges of each of thecomponents of various compositions are contemplated. Furthermore, morethan one organic binder could be used, as could more than one inorganicbinder. In a specific example, the inorganic binder solution is presentin an amount about 55.5% by weight of the total weight of the corematrix in wet mixture, with the binder solution comprising sodiumsilicate and water. More specifically, the inorganic binder solutioncomprises sodium silicate present in an amount between 40% and 60% byweight and water present in an amount between 40% and 60% by weight. Inmany cases, the inorganic binder solution will comprise a 1:1 ratio ofsodium silicate to water. The sodium silicate may be pre-mixed and thesolution provided in liquid form, or the sodium silicate may be inpowder form and subsequently mixed with water.

In one aspect, the latex or organic binder can be present in an amountabout 7.4% by weight of the total weight of the core matrix in wetmixture, and comprises an ethylene polyvinyl acetate (EVA) emulsion. Thelatex binder facilitates formation of a flexible, porous compositionthat is subsequently formed into the core matrix of the shear panel. Oneparticular example of latex binder used is ethylene vinyl acetate(water-based binder) sold under the trademark Airflex (e.g., Airflex420), which is manufactured and sold by Airproducts, Inc. Thisparticular binder is used to facilitate the flowable and formableformation of the core matrix, as well as to provide either flexible orsemi-rigid compositions. The latex binder can be pre-mixed with water tobe in liquid form. The latex binder comprises EVA present in an amountabout 40% by weight, and water present in an amount about 60% by weight.In one aspect, the latex binder can range from about 2.5 wt % to about30 wt % of the total weight of the core matrix in wet mixture. In afurther aspect, the latex binder can range from about 5 wt % to about 20wt %. Non-limiting examples of latex binders include those produced byAirflex (including specifically 323, 401, 420, 426), those produced byUCAR (specifically 154s, 163s), conventional glues and pastes, thoseproduced by Vinac (including XX210), and mixtures and combinationsthereof.

Optionally, water soluble polymers can be included in the core matrixformulation. The water soluble polymer may be added to the core matrixcomposition already dissolved in water or in dried form. The function ofthe water soluble polymer is to serve as a stabilizer for any surfactantor foaming agent present in the mixture. Specifically, the water solublepolymer helps to stabilize the composition until the binder is eithercured or cross-linked. Non-limiting examples of water soluble polymersthat can be included in the formulation include those distributed byAirflex, such as polyethylene oxide, such as, e.g., WSR 301. The watersoluble polymer can also function as a thickener and prevent the waterfrom running out. Such polymers can be useful to control the stiffness,flexibility, tear strength, and other physical properties of thebuilding material, as well as to stabilize any surfactants, if present.In some embodiments, it may be desirable to eliminate, or at leastsignificantly reduce, the amount of organic components in the corematrix composition. This is particularly the case in the event it isdesirable that the building material comprise more enhanced fireresistant properties. The amount of organic components remaining in thecore matrix composition, therefore, may be dependent upon the particularapplication.

Airflex products further include, and therefore the core matrixcomposition further includes, a water soluble polymer namely apolyethylene oxide, such as WSR 301. The water soluble polymer functionsas a thickener and prevents the water from running out. These also areused to control the stiffness, flexibility, tear strength, and otherphysical properties of the shear panel, as well as to stabilize anysurfactants, if present.

As mentioned, depending upon the type used, the binder may be simplycured, with no cross-linking, or it may be caused to polymerize orcross-link. By cross-linking the binder(s), a stronger more permanentphysical coupling occurs between the binder and the microparticles. Assuch, the present invention contemplates using one or more means toeffectively cross-link the binders. In one exemplary embodiment, thebinders may be cross-linked by elevating the temperatures of the bindersto a suitable temperature for a suitable period of time to effectuatepolymerization and bonding. This may be done using conventional radiantheating methods, or it may be done using microwaves applied continuouslyor at various intervals, as well as with microwaves of differentintensities. Using microwaves is significantly faster, and much morecost effective. In addition, cross-linking with microwaves functions toproduce a stronger shear panel building material as the amount of binderactually cross-linked is increased.

Cross-linking within a shear panel building material providessignificant advantages over a shear panel building material having anengineered wood product composition that is not cross-linked. Forexample, with cross-linking, the binders are made stronger, they do notabsorb water as easily, and the connection between microparticles ismuch stronger. In addition, the shear panel building material does notweaken over time. Other advantages may be realized by those skilled inthe art. Having said this though, there may be applications wherecross-linking is not preferred, and where a non-bonded composition isbetter suited. This of course, is contemplated herein.

The present invention further contemplates utilizing a surfactant orfoaming agent, mixed with the binder and the microparticles to achieve ashear panel building material having a relatively low density.

With respect to a foaming process, once ingredients are combined, theyare whipped or agitated to introduce air into the mixture, and thendried. Mechanical agitation or compressed air may be used to physicallyintroduce air into the mixture and to create the foaming process. Thefoaming process effectively causes microparticles to be supported in amuch more separated position with respect to one another as compared toa non-foamed composition. With the presence of the foam, themicroparticles suspended and are able to dry in more dispersedconfigurations. In another aspect, the suspension of the microparticlesdue to the presence of the foaming agents may also function to makecertain core matrix compositions more flowable or pumpable, as well asmore formable.

Non-limiting examples of surfactants or foaming agents include, anionicfoaming agents, such as Steol FS406 or Bio-terge AS40, cationic foamingagents, and non-ionic foaming agents, etc.

The present invention further contemplates use of a water solublepolymer in the composition making up the shear panel building material.The water soluble polymer may be added to the core matrix compositionalready dissolved in water or in dried form. The function of the watersoluble polymer is to serve as a stabilizer for any surfactant orfoaming agent present in the mixture. Specifically, the water solublepolymer helps to stabilize the composition until the binder is eithercured or cross-linked.

The density of the shear panel building material, namely the corematrix, having the composition just described is between 0.4 g/ml and0.6 g/ml.

The core matrix 14 may further comprise one or more additives orfillers. These may be present in an amount between 0.01 and 50% byweight of the total weight of the core matrix in wet mixture. In oneexemplary embodiment, the microparticles may be blended with expandedsiliceous inorganic particles, such as perlite, to lower the density ofthe shear panel building material, decrease its weight, and reducemanufacturing costs. Specifically, it is contemplated that expandedsiliceous inorganic particles may replace a portion of microparticles inan amount between 1% and 50% by weight of the total weight of the corematrix in wet mixture.

Alternatively, the core matrix can be substantially free of variousadditives and/or fillers. For example, the core matrix can optionally befree of any or all of fiberous discrete particles, fiberous materials,cements, glues, adhesives, etc. Furthermore, the shear panel buildingmaterial, in one aspect, is not a laminate material. It should be noted,however, that multiple layers of shear panel and/or similar wallboardmaterial can be layered into a laminate, if desired.

The core matrix may further comprise a setting agent configured orintended to enhance the water resistant properties of the buildingmaterial, and particularly the core matrix of the building material. Inone exemplary embodiment, the setting agent may comprise Class C flyash. In another exemplary embodiment, the setting agent may comprisezinc oxide. In still another exemplary embodiment, the setting agent maycomprise sodium fluorosilicate.

In exemplary core matrix compositions utilizing a setting agent,microspheres may be combined with an inorganic binder (e.g., sodiumsilicate solution (comprising sodium silicate and water)) in a 1:1ratio, with the core matrix composition a setting agent present in anamount between about 10% and about 30% of the total weight of theinorganic binder. For example, the core matrix composition may comprise,as the setting agent, Class C fly ash present in an amount between 15and 25% of the total weight of an inorganic binder. In another example,the core matrix composition may comprise, as the setting agent, eitherzinc oxide or sodium fluorosilicate present in an amount between about 5and 15% of an inorganic binder. If an organic binder component is alsoto be used, such may be combined in an amount between 5 and 20% of thetotal weight of the inorganic binder component.

Unlike similar shear panel building materials formed having amicroparticle/binder core matrix disposed between opposing paper facingmembranes, the present invention shear panel building material 10preferably comprises at least one stiff or rigid (or semi-stiff orsemi-rigid) facing membrane to enhance the strength and othercharacteristics of the shear panel building material (e.g., to enhancethe thermal characteristics, to enhance the sound attenuationcharacteristics, to function as a vapor barrier, etc.). However, twopaper or other flexible facing membranes may be utilized, with a metalor other rigid material present as a reinforcing member in order toprovide the enhanced functionality made possible by the rigid member. Inanother aspect, each of the facing membranes may comprise a rigid orsemi-rigid metal or plastic material. In the exemplary embodiment shown,the first and second facing membranes 34 and 54 each comprise a paperfacing sheet similar to that found on various types of drywall products.Of course, as stated, at least one or both of the first and secondfacing membranes may comprise a rigid or semi-rigid material. Indeed,the shear panel building material 10 may comprise many different typesof materials or combination of materials, thus enabling the shear panelbuilding material to exhibit various properties or characteristics.

In one aspect, the reinforcing member is a rigid material. The rigidmaterial can, in one aspect, have substantially the same height andlength as one or both facing membranes, and can optionally be arrangedsubstantially parallel to at least one of the facing membranes. Therigid material can be a mesh or a continuous sheet of material. Therigid material may also be self-supporting, meaning that the rigidmaterial has a defined shape and attachment to itself outside ofattachment to or within the core matrix. To contrast, materials that arediscrete particles or are materials that are infiltrated into othermaterials are not considered self-supporting.

The reinforcing member 74 optionally disposed between the outer facingsheets may also comprise many different types of materials. In addition,the shear panel building material 10 may comprise multiple or aplurality of reinforcing members located or positioned within the corematrix, between an outer surface of the core matrix and a facing sheet,or a combination of these. In one aspect, the reinforcing material 74comprises a plastic or a plastic film. However the reinforcing material74 may also comprise metals or metal alloys (quilted or non-quilted),fiberglass, fiberglass sheet/cloth, Kevlar, nylon, graphite/composites,plastic fibers/fabric, any kind of woven fabric, woven or nonwovenfibers or fiber sheets, and any combination of these as recognized bythose skilled in the art. In addition, the reinforcing material maycomprise any desired thickness. In another aspect, the reinforcingmaterial 74 may comprise loose fibers that are mixed in with themicroparticles and binder composition, thus being integral with themicroparticles and binder within the core matrix. In the exemplaryembodiment shown in FIG. 2, the reinforcing member 74 comprises analuminum sheet sandwiched midway within the core matrix 14 between thefacing membranes 34 and 54. The aluminum or quilted aluminum provides asealing function, while also functioning to improve sound absorption andresist heat or thermal transfer. Aluminum is a good choice because it islightweight, fire resistant, and provides added strength to the shearpanel. However, other materials may be used, such as other metals,galvanized steel, plastic, etc. These would most likely also be quilted.

The reinforcing member 74 is configured to reinforce or enhance one ormore properties or characteristics of the shear panel 10. For example,the reinforcing member 74 may be configured to reinforce against (orimprove the resistance of) sound transmission, heat transfer or anycombination of these. The reinforcing member 74 may also be configuredto enhance the overall strength of the shear panel building material 10,thus further countering the effects of lateral loads acting on astructure built with the present invention shear panel buildingmaterial. In one aspect, the shear strength of the shear panel can beabout the same as an OSB of the same size.

With reference to FIG. 3, illustrated is a shear panel building materialin accordance with another exemplary embodiment of the presentinvention. In this particular embodiment, the shear panel 110 comprisesmany of the same components as the shear panel 10 discussed above andshown in FIG. 2. As such, the discussion above is incorporated herein,where appropriate and applicable. Unlike the shear panel 10 of FIG. 2,however, the shear panel 110 of FIG. 3 does not comprise a reinforcingmaterial sandwiched within the core matrix 114. Rather, the shear panel110 simply comprises a core matrix 114 disposed between a paper facingmembrane 134 and a quilted aluminum facing membrane 154. Because noadditional reinforcing material is used, the rigid or semi-rigidaluminum or other metal/plastic facing membrane 154 may comprise anincreased thickness over the thickness of the same facing membrane ofFIG. 2. However, such an increased thickness may not be necessarydepending upon the application. No matter the location of the rigid orsemi-rigid material, in one aspect, the thickness of the rigid orsemi-rigid material can be from about 2 to about 3 lbs/sq. yd. In oneaspect, the rigid material can be metal lathe as normally associatedwith masonry brick work.

With reference to FIG. 4, illustrated is a shear panel building material10, formed in accordance with one exemplary embodiment of the presentinvention, just prior to being installed on or hung from a stud wall 2.Specifically, shear panel building material 10 comprises the samecomponents as that of FIG. 2. It should be noted that no specializedinstallation techniques are required for installing or hanging the shearpanel building material 10. The shear panel building material 10 may beinstalled in a similar manner as conventional OSB or other similar shearpanel products. However, FIGS. 5-A and 5-B illustrate other exemplaryembodiments of shear panel building materials that may require one ormore special installation techniques. These embodiments are discussed indetail below.

With reference to FIGS. 5-A and 5-B, illustrated are two differentexamples of coupling and sealing systems, each one being incorporatedinto a present invention shear panel building material, and each onebeing configured to couple adjacent shear panels together, and to sealor at least partially seal (e.g., not necessarily a strictly airtightseal) the adjacent shear panels. The coupling and sealing system isintended to reduce and/or eliminate the flanking path between theadjacent shear panels at the joint. The seal may be further enhanced orimproved upon nailing, screwing or otherwise securing the joint to astud in a stud wall. Indeed, the overlap shown is intended to bepositioned about a stud, but this may or may not always be possible. Theseal functions to resist sound transmission through the joint, and alsoto resist heat transfer through the joint, by creating a more complexflanking path for heat transfer and sound transmission. In other words,the flanking path is intended to be reduced and/or eliminated ifpossible by the coupling and sealing system of the present invention.

With specific reference to FIG. 5-A, illustrated are partial end viewsof a first shear panel building material 210-A and a second shear panelbuilding material 210-B, each one formed in a manner as describedherein, namely as comprising a core matrix 214-A and 214-B,respectively, first facing membranes 234-A and 234-B, respectively, andsecond facing membranes 254-A and 254-B, respectively, and reinforcingmembers 274-A and 274-B, respectively. The first shear panel buildingmaterial 210-A comprises a protruding or male configuration 218 formedwithin and along an edge of the core matrix 214-A, which is intended toalign and mate with a corresponding recess or female configuration 222formed within and along an edge of the core matrix 214-B of the secondshear panel building material 210-B. The coupling or connection isdesigned to secure the first and second shear panel building materials210-A and 210-B, respectively, in a proper position with respect to oneanother, and to permit the edges of the membranes 234-A and 254-A of thefirst shear panel building material 210-A to meet the membranes 234-Band 254-B of the second shear panel building material 210-B. Thecoupling system further helps to maintain proper positioning afterinstallation. The coupling system may be formed about any of the edgesof the shear panel building material.

FIG. 5-B illustrates partial end views of a first shear panel buildingmaterial 310-A and a second shear panel building material 310-B, eachone formed in a manner as described herein, and including reinforcingmembers in the form of rigid members 374-A and 374-B, respectively. Thefirst shear panel building material 310-A comprises a notch 326 formedwithin and along an edge of the core matrix 314-A, with the surfaceparallel to the surface of the membranes 334-A and 354-A optionallycomprising a nub 328, also formed from the core matrix 314-A. The notch326 is intended to align and mate with a corresponding notch 330 formedin the second shear panel building material 310-B to couple together thefirst and second shear panel building materials. The notch 326optionally comprises a recess 332 that receives nub 328 therein when thefirst and second shear panel building materials are secured or coupledto one another. The coupling system shown in FIG. 5-B is intended toperform a similar function as the coupling system shown in FIG. 5-A.

It is noted that the coupling system is integrally formed into the corematrix during manufacture of the shear panel building material. Theunique composition of the core matrix provides this capability. Theparticular size, shape or configuration of the coupling system may vary,and may be formed in accordance with various different manufacturingtechniques.

It also contemplated that one or more sealing members or adhesives maybe applied to the coupling system to enhance the sealing functionachieved by coupling the two shear panels together.

FIG. 6 illustrates a shear panel building material in accordance withstill another exemplary embodiment of the present invention. In thisparticular embodiment, the shear panel 710 also comprises many of thesame components as the shear panel 10 discussed above and shown in FIG.2. As such, the discussion above is incorporated herein, whereappropriate and applicable. However, unlike the shear panel of FIG. 2,the shear panel 710 comprises a core matrix 714 disposed between firstand second paper facing membranes 734 and 754, as well as tworeinforcing materials 774-a and 774-b disposed at evenly spacedpositions within the core matrix 714. The first reinforcing material774-a comprises a woven fabric. The second reinforcing material 774-bcomprises an aluminum sheet. This particular embodiment illustrates thatmultiple or a plurality of reinforcing materials may be used, andpositioned in various locations.

FIG. 7 illustrates a shear panel building material in accordance withyet another exemplary embodiment of the present invention. In thisparticular embodiment, the shear panel 810 also comprises many of thesame components as the shear panel 10 discussed above and shown in FIG.2. As such, the discussion above is incorporated herein, whereappropriate and applicable. However, unlike the shear panel of FIG. 2,shear panel 810 comprises a core matrix 814 disposed between a firstpaper facing sheet 834 and a second quilted aluminum facing membrane854, with a reinforcing member 874 comprising a woven material beingdisposed or sandwiched within the core matrix 814.

From the foregoing description, and the corresponding drawings, itshould be apparent to those skilled in the art that many differentcombinations and types of components may be used to provide a shearpanel formed in accordance with the present invention, and withdifferent performance characteristics.

The present invention shear panel building material provides manyimproved properties and characteristics over conventional shear panelbuilding materials, such as OSB. For example, the present inventionshear panel building material has a significantly lower heat transferthan OSB. In other words, the present invention shear panel is able toprovide a much greater resistance to thermal heat transfer (e.g., forfire resistant or insulating applications) than OSB. The specificproperties with respect to heat transfer may range or vary dependingupon the makeup of the composition, such as the ratio of microparticlesto binder, the type of binder(s) used, the location and type of areinforcing material, etc. the type and thickness of the facingmembranes, as discussed herein. In addition to weighing less, thepresent invention shear panel building material is significantlystronger than OSB.

Perhaps the most significant advantage over conventional shear panelproducts is the ability for the present invention shear panel buildingmaterial to attenuate or absorb sound. Indeed, the Sound TransmissionClass (STC) rating was found to be significantly better than OSB andother shear panel types.

The process used to make the present invention shear panel buildingmaterial can be described generally by the following steps. The firstbinder solution is obtained. For example, a sodium silicate binder maybe dissolved in water to form the first binder solution. Alternatively,a pre-mixed sodium silicate solution may be obtained. A second bindersolution is obtained. For example, a polyvinyl acetate latex binder maybe used. In addition, a water soluble polymer may be obtained.Alternatively, this may be included in the latex binder, such as is thecase with the Airflex 420 product. The right size and quantity ofmicrospheres are then blended with the first and second binders in acontinuous process (e.g., in a static mixer) to obtain the formable corematrix composition, in wet mixture. The formable core matrix is thendisposed from the static mixer onto a facing membrane supported within aforming pan. Alternatively, the formable core matrix may be disposedwithin a mold. An opposing facing member is added to the formable corematrix. Alternatively, a reinforcement material is added to the formablecore matrix, with additional formable core matrix being subsequentlyadded to the reinforcing material, and finally an opposing facing memberadded to the additional formable core matrix.

Each of these produce a green material product, which may then besubjected to pressure (e.g., from rollers, etc.) to compress the corematrix and facing membranes to a desired thickness. Once in proper form,the green material is subjected to elevated temperatures or microwavesto cure or cross-link the binder(s). In one exemplary embodiment, thegreen material is placed within an oven set between 200° and 400° F. forbetween 15 and 60 minutes in order to cure or cross-link the binders andto obtain the final shear panel building material product.

In another exemplary embodiment, the green material is subjected tomicrowave radiation to cure or cross-link the binders and to achieve thefinal shear panel product. Using microwaves is advantageous over ovencuring in that the final shear panel product may be achieved in muchquicker time. The green material may be subject to continuouslyoccurring microwaves, or microwaves occurring in intervals. In addition,different power setting may be used to control the temperature withinthe green material. Any combination of microwave frequencies, durationof time, progressive increases or decreases in power, etc. may beemployed as determined by one skilled in the art. However, the greenmaterial preferably is not exposed to microwaves that are so strong orfor too long a duration so as to cause the water within the core matrixcomposition (e.g., the water within the binders) to boil. Boiling thewater may tend to cause the microparticles to unduly separate, thusleaving large voids or defects in the core matrix. It is desirable touse microwaves to cause the water in the green material to steam andevaporate without creating steam pockets that would lead to theaforementioned voids. Therefore, the microwaves should be controlled soas to minimize the potential for such voids.

Exposing the green material to microwaves also functions to cure orcross-link the binders. As such, controlling the duration, frequency,power, etc. of the microwaves to effectuate cross-linking iscontemplated.

Another advantage of using microwaves is that the green material iscured, the water evaporated, and the binders cross-linked from theinside out, rather than the outside in as with oven curing. This mayresult in a more uniform cross-link distribution, achieved in a muchquicker time over oven curing.

It should be noted that in the event one of the facing membranescomprises a metal facing membrane, this may be added after formation(e.g., curing or cross-linking) of the core matrix. If the reinforcingmaterial is metal, the building material may be formed by repeating thesteps above, with the resulting two or more green materials beingadhered or otherwise coupled together. In other words, a metal facingmembrane or reinforcing material is intended to be added after formationof the core matrix.

The method of manufacturing the present invention shear panel buildingmaterial may further comprise applying a binder solution to one or bothof the facing membranes prior to disposing the core matrix thereon ortherebetween. By applying it is meant that the facing membrane may becoated with a binder solution, or completely or partially saturated withthe binder solution.

Upon heat curing, the water content of the shear panel building materialcan be less than about 5 wt %, and further less than about 2 wt % oreven less than about 1 wt %.

The facing membrane 34, and/or 54 shown in FIG. 2, may comprise manydifferent types of materials or combination of materials, and maycomprise different properties. In one exemplary embodiment, facingmembranes 34 and/or 54 can each be independently selected. One or bothfacing membranes can comprises a paper material similar to that found onvarious wallboard and/or shear panel products.

As the final product is desirably a cohesive one, in one aspect, thecore material and facing sheet of the shear panel can be optimized forproper or superior adhesion, thus ensuring the facing sheet will remainsecured to the core material. As such, additional binder or binders atthe surface level can be utilized to improve adhesion of a facing sheetto the core matrix. Alternatively, a different adhesive agent can beutilized to improve adhesion of a facing sheet to the core matrix. Assuch, additional binder can be utilized to improve adhesion of a facingsheet to the core matrix. Alternatively, a different adhesive agent canbe utilized to improve adhesion of a facing sheet to the core matrix.

A multi-elevational surface configuration may be utilized, wherein oneface of the shear panel is without a facing membrane, and thereforeexposed, and includes a non-planar facial arrangement. The purpose ofproviding a multi-elevational surface configuration formed about onesurface, particularly the exposed surface, of the core matrix is atleast twofold—1) to significantly further enhance the sound attenuationor damping properties of the building material, namely to ensureacoustic isolation and absorption over a wide range of frequencies, and2) to enhance the flex strength of the building material by eliminatingshear lines. As will be described below, many differentmulti-elevational surface configurations are contemplated herein. Thoseskilled in the art will recognize the benefits of providing a series ofpeaks and valleys about a surface to create different surfaces locatedin different elevations, as well as different surfaces oriented ondifferent inclines, particularly for the specific purpose of attenuatingsound. Sound waves incident on these different elevational and/ororiented surfaces are more effectively attenuated.

Referring now to FIG. 8, illustrated is a building material formed inaccordance with another exemplary embodiment. In this particularembodiment the building material 1210 comprises a core matrix 1214, arigid material 1254 disposed or sandwiched within the core matrix 1214,and a facing sheet 1234 comprised of tar paper. With this configuration,the building material 1210 may be used as a finishing material on theexterior of residential or commercial structures, replacing stucco. Thebuilding material 1210, comprising pre-formed panels, can be mounted orsecured to the exterior walls 1202 of a structure, say a residentialhome, much in the same way a wallboard is mounted or secured to theinterior walls of a home. Once secured in place, a stucco finish 1204commonly known in the art may be applied to the panels to create afinished look. The stucco finish can be applied so as to sufficientlyconceal any seams or gaps between adjacent building material panels.Some obvious advantages that result from providing exterior finishingpanels is the elimination of the labor intensive task of securing metallath to the exterior walls, subsequently applying plaster over the metallath, and then waiting several days for the plaster to dry and set priorto being able to apply the stucco finish. With the pre-formed buildingpanels shown herein, installers can mount the panels and apply thestucco finish immediately, thus significantly reducing labor and costs.

It is contemplated that such a building panel may be applied to shearpanels, such as oriented strand board, to shear panels formed after themanner of the present invention, or directly to a stud frame, whereinthe building panel may function as the shear panel and also receive thestucco finish directly thereto, thus eliminating the need for a separateshear panel.

Shear panels as described herein exhibit superior qualities to manysimilar materials currently available. Furthermore, the superiorqualities co-exist, where a material may exhibit both mold resistanceand enhanced acoustic properties simultaneously. The core matrix won'tgrow mold. The shear panel is generally resistant to water, and evensubmersion in water for extended periods of time. The material can beformulated to be fire resistant.

Testing was completed on a wallboard composition, similar to the shearpanel design but without a rigid member. The results generally areapplicable to the shear panel as they both contain the same core matrixcomposition. The wallboard exhibits strong flexural strength up to twotimes that of conventional gypsum wallboard (e.g., 280 lbs vs. 140 lbs).Furthermore, the wallboard can withstand impacts without crumbling ordisplacement in surrounding areas such as a corner. the wallboard(including microspheres, sodium silicate, and an organic binder) wasfound to exhibit flexural strength range 137.2 lbf to 164.9 lbf, average153 lbf; nail pull 72-87 lbf, average 78 lbf; weight of 4 inch by 8 inchby ½ inch sheet average 42.1 lbs; acoustic transmission based on avariety of frequencies ranging from 80 to 8000, average 50.9 db; R valuerange 16.2 to 19, average 17.5; mold resistance found no measurable moldgrowth; fire resistance testing found no combustion for exposure topropane torch flame for 15-120 minutes; and edge hardness 14-16 lbf,average 15.1 lbf. As shown, the wallboard material excels in a pluralityof desirable qualities and provides a superior construction material.

Additional testing was completed on wallboard material (includingmicrospheres, sodium silicate and vinyl acetate/ethylene copolymer,where the wallboard is ½″ thick, the sodium silicate to cenosphereweight ratio is about 1:1, the sodium silicate to EVA weight ratio isabout 10:1, the cenospheres are 300-600 microns). Unless otherwisenoted, the testing was compared to baseline gypsum wallboard and thepresent invention board and gypsum wallboard were ½ inch thick. Thefollowing results were collected:

Surface finish—no noticeable difference in the surface finish.Snap and dust—wallboard material of the present invention would snapcleaner with a straighter and more square line and did not produce theamount of dust that gypsum wallboard did.Flexural strength—(according to ASTM C 473-03) gypsum wallboard hadnormal breaking at 140 lbs of force. The present invention wallboard hada minimum of 160 lbs force, with many samples obtaining 10-12% highervalues.Nail pull resistance—(according to ASTM C 473-03) 85-90 lb ft. comparedto gypsum 77 lb ft.Dimpling—dimpling yielded a more consistent pattern without crushing theboard or creating micro fractures in localized areas. Gypsum boardcrushes and creates microfractures. Dimpling testing, along with nailand screw tests in extreme edges were similarly favorable.Edge crush—(striking edges on right angle metallic surface of weightedsamples) slight indentation, but relatively unharmed compared to gypsumbeing easily damaged.Weight—with various component ratios, minimal weight reduction overgypsum wallboard was 20%, maximum weight reduction over 30%.Mold growth—(according to ASTM D 3273) board was non-fungus nutrient anddoes not support mold growth.Water resistance—(immersed board in water and tested frequently to seewhen core would soften) board withstood minimum of four days underwater, totally submerged before softening was found. Many samples lastedmore than one month without softening. Gypsum board softens withinseveral hours and crumbles apart within about one day.Fire resistance—(direct propane flame, torching one side of the materialwhile measuring thermal rise on opposite side) flame side paper wouldscorch and smolder away with a time factor similar to the paper ofgypsum, which was less than about 2 minutes. The board would then have agradual thermal rise over the next 20 minutes to 350 degrees C. Gypsumboard rises to 80 degrees C. in about 2 minutes and maintains thattemperature for 5 minutes, then rises quickly to 400 degrees C. after 20minutes.K value—value of about 0.07 compared to gypsum board's K value of 0.11.This translates to gypsum's lower performance by transferring heatfaster than the inventive board.

EXAMPLES

The following examples illustrate embodiments of the invention that arepresently known. Thus, these examples should not be considered aslimitations of the present invention, but are merely in place to teachhow to make the best-known compositions and forms of the presentinvention based upon current experimental data. Additionally, someexperimental test data is included herein to offer guidance inoptimizing compositions and forms of the utility material. As such, arepresentative number of compositions and their method of manufactureare disclosed herein.

Example 1 Testing of Utility Material of Cenospheres and Sodium Silicate

A mixture of cenospheres of the form of Extendospheres™ and sodiumsilicate were combined and allowed to dry and form a fire-resistantinsulating material Extendospheres™ of a 300-600 micron diameter sizerange were combined with sodium silicate solution (O type from PQcorporation) in a 1:1 weight ratio. The wet slurry was poured into acavity around the turbine and allowed to dry. It formed a hardened massof Extendospheres™ and sodium silicate. The material was tested with anIpro-Tek single spool gas turbine. The tests showed that the materialhas a high insulation capacity, and the ability to withstand heat. Theinsulation was exposed to temperatures of up to 1200° C. However, it wasfound that when the material is exposed directly to flames for periodsof more than a few minutes, it cracks and blisters and begins to losephysical strength.

Example 2 Formation of Mold to Form Wallboard

In one aspect, the utility material can be wallboard panels. The panelscan optionally be formed by exposing an uncured wallboard to microwaves.Such formation, as well as general wallboard formation, can utilize amold. An example of a mold can be made up of a vinylester resin moldhaving top and bottom pieces. To form the vinylester resin mold, a woodmold is first constructed. The wood mold can be formed according to theshape and dimensions as illustrated in FIG. 9.

To form the vinylester resin mold, an outer mold of wood is attached tothe base of the wood mold using double sided tape. Any releasable binderor means of attaching can be alternatively used. A resin mixture isformed of 97.5 wt % vinylester resin mixed with 2.5 wt % methyl ethylketone peroxide (MEKP) catalyst. Microspheres of the form ofExtendospheres and the resin mixture are added in a 1:1 ratio to form acore mixture. The core mixture is mixed well using a stirring devicethat was mounted in a drill such as you would use to mix paint. Mix timewas about 3 minutes. The core mixture is poured into the prepared woodmold and distributed to cover the full mold, including all corners. Themixture is gently smoothed out, although not pressed into the mold usingshort dropping, manual shaking, mechanical vibration, and spreadingtools such as trowels. The mixture is not pressed into the wood mold aspressing it can decrease the porosity of the resulting vinylester resinmold and can make it unusable. The mixture is cured at room temperatureuntil it is rigid and strong to the touch. The curing time is typicallyabout three hours. The porous vinylester resin mold is then carefullyremoved. The resulting vinylester resin mold has a cavity 11.625 inchesby 15.25 inches by 0.5 inches deep, with a 0.375 inch wall around theoutside edge. A top piece for the vinylester resin mold is formed usingthe same procedure and results in a mold in a rectangle havingdimensions of 12.375 inches by 16 inches by 0.5 inches deep.

Example 3 Preparation of Wallboard Using Mold

As noted, the utility material can be in the form of wallboard panels.The panels can optionally be formed by using the porous vinylester resinmold. First, a wallboard backing paper is cut using a backing papertemplate as shown in FIG. 10. Although a particular backing paper shapeis illustrated, it should be understood that the backing paper can be ofany shape or size sufficient to form a segment of wallboard. Facingpaper is cut to a rectangle sized just smaller than the greaterdimensions of the backing paper. In the present embodiment, the facingpaper is cut to an 11.625 inch by 15.25 inch rectangle. The backingpaper is folded and placed in the porous mold. A wallboard mixture maybe formed using:

-   700 to 900 g microspheres-   1100 to 1300 g sodium silicate solution, such as that sold by “O”-   300 to 500 g latex binder-   20 to 30 cc foaming agent

Specifically, the foaming agent is added first to the sodium silicatesolution and mixed using a squirrel mixer at 540 RPM for 2 minutes. Thelatex binder is added to the mixture and mixed for an additional 30seconds on the same settings. The microspheres are added slowly whilemixing, over 1 to 2 minutes, until the mixture is uniform.

The wallboard mixture is poured into the lined mold and leveled outusing a spatula or paint stick. It should be noted that any tool ormethod could be used at this point to level the mixture. The mixture isfurther leveled by vigorous shaking. The sheet of facing paper is placedon top of the mixture and covered with the top panel of the vinylesterresin mold. The mold is placed in a microwave and the panel is radiatedfor the desired amount of time. Preferably, the mold is turned often toproduce a more even drying of the panel. The panel should not besubjected to continuous radiation for any extended amount of time toreduce or prevent large voids in the wallboard core. The power level ofthe microwave radiation can be set to control the amount of time themicrowave is on. The time on and off of the microwave can be accordingto Table 1:

TABLE 1 Power Level Time On (Seconds) Time Off (Seconds) 1 3 19 2 5 17 37 15 4 9 13 5 11 11 6 13 9 7 15 8 17 5 9 19 3 10 22 0Once properly heated, the resulting panel of wallboard can be carefullyremoved from the mold.

Example 4 Flexural Strength Testing

An important feature of wallboard is the flexural strength of the board.Each sample board was prepared by forming a core matrix materialincluding the components outlined in Table 2 and spreading the mixtureinto a mold cavity and leveling it off The resulting sample is 0.50inches thick and 2 inches wide. Each sample is dried in an oven at 100°C. until dry as determined by Aquant moisture meter. The sample issuspended between two supports that are 6 inches apart so that 1-1.5inches rests on either side of the support. A quart size paint can isplaced in the center of the suspended sample and slowly filled withwater until the sample breaks at which point the weight of the can ismeasured and recorded. Flexural strength is important for normalhandling, installation, and use. Strength at least equal to gypsumwallboard was desired, for uses wherein the wallboard could replaceconventional gypsum wallboard. Each wallboard includes a differentcomposition as outlined in Table 2.

TABLE 2 Ceno- Dry Weight spheres Binder Foaming weight to break Run (g)Water (g) (type, g) Agent (g) (g) (kg) 1 50 6.0 O, 52.4 1.0 70.2 5.0 250 0 O, 87.2 2.0 83.7 20.6 3 50 14.1 RU, 42.9 1.0 70.2 4 50 14.4 RU,71.4 2.0 83.6 18.0 Foam 50 20 RU, 71.4 16.4 83.6 9.2 5 50 8.0 BW-50, 1.070.2 5.1 47.6 6 50 7.0 BW-50, 2.0 83.7 7.4 79.2

The ingredients in each row were combined then mechanically whipped toproduce a foamed product. The foamed product was then cast in a mold.All binders used are sodium silicate based. Type O binder is a viscoussodium silicate solution from PQ Corporation. Type RU binder is alsofrom PQ Corporation and is a sodium silicate solution that is similar toO type but not as viscous. RU type is more watery and has a lower solidscontent. And, type BW-50 binder, also from PQ Corporation. BW-50 is alsoa sodium silicate solution, and has a lower ratio of silica to disodiumoxide. As illustrated, the amount and type of binder can be optimized tocreate a wide range of flexural strengths.

Example 5 Flexural Strength Testing II

Flexural strength testing was conducted on seven sample boards accordingto the procedure outlined in Example 4. The components of each sampleboard and the flexural strength testing weight are recorded in Table 3.

TABLE 3 Weight Weight Weight to to to break break break Foaming Dry(kg)- (kg)- (kg) - Cenospheres Water Binder Agent weight no Manillacard- Run (g) (g) (g) (g) (g) paper folder board 1 50 17.9 14.3 1.0 56.72 50 15.5 28.6 1.0 63.5 2.06 3 50 12.1 42.9 1.0 70.2 11.96 21.55 4 5014.3 57.1 2.0 76.9 14.37 5 50 14.4 71.4 2.0 83.6 15.35 26.89 36.65 6 5011.6 85.7 2.0 90.4 21.8 7 50 9.4 100.0 2.0 97.1 20.85 29.40 34.99Ceiling  5.57 Tile ½″ thick Dry 26.91 wall ½″ thick

As illustrated, increasing the density and increasing the binder contentin the sample generally results in stronger samples. Increasing theamount of water in the sample mixture generally decreases the density ofthe mixture and results in decreased strength of the sample. In thesamples including testing with a Manilla folder and/or cardboard, thenoted material was placed on both sides of the sample. Such arrangement,with the core material flanked by a paper product, is comparable toconventional gypsum wallboard. As illustrated, the inclusion ofpaperboard on both sides, either in the illustrated form of Manillafolder or cardboard, significantly increased the sample's strength.

Example 6 Flexural Strength Testing III

A number of sample panels were formed according to the procedureoutlined in Example 4, with the exceptions that strips of paper of thenoted thickness to 2 inches wide by 11 inches long. One strip is placedin the mold cavity before pouring in the core matrix material. Afterpouring and leveling the mixture, another sheet of the same thickness isplaced on top of the mixture. The mixture is covered with wire mesh andweighed down to keep it in place during drying. For the results listedbelow, the paper did not properly adhere to the core matrix, so the testresults reflect samples having only one sheet of paper attached. Theflexural strength tests were performed paper side down. Presumptively,the results would be higher for a sample including both facing sheets.

The core matrix material for each sample included 250 g Extendospheres,40 g water, 220 g binder, 10 g foaming agent. The dry weight for eachsample is 334.9. For paper having a thickness of 0.009″, the weight tobreak was 6.6 kg. For paper having a thickness of 0.015″, the weight tobreak was 7.5 kg. For paper having a thickness of 0.020″, the weight tobreak was 5.2 kg.

Example 7 Additional Testing on Sample Boards

A number of sample panels were formed in accordance with the methods andcompositions outlined in the previous Examples. Typically, a mixturesuch as that given above is cast in a mold comprising paper disposedabove and below the core and a frame around the perimeter of the sampleto contain the wet core material while it dries and cures. After dryingand heating the wallboard sample can be tested for mechanicalproperties. The composition of each sample and the associated resultsare illustrated in Table 4.

Flexural Strength Testing—“Flex”

A 0.5 inch thick sample that is 2 inches wide by 6 to 8 inches long isplaced on the test fixture and is thus suspended between two legs. Thelegs are approximately 4.25 inches apart. The test apparatus is equippedwith the flexural test attachment, with the bar on the attachmentsituated parallel to the test specimen. The flexural test attachment iscentered midway between the legs of the test fixtures. A bucket ishooked to the end of the test apparatus and weight is slowly added tothe bucket until the test specimen fails. The weight of the bucket ismeasured to obtain the Flex results.

Nail Pull Resistance Testing

A 0.5 inch thick sample that is 6 inches wide by 6 inches long isdrilled to have a 5/32 inch pilot hole in the center of the sample. Thesample is placed on a nail pull fixture, with the pilot hole centered onthe 2.5 inch diameter hole in the nail pull fixture. A nail is insertedinto the pilot hole. The shank of the nail should be approximately 0.146inches in diameter, and the head of the nail should be approximately0.330 inches in diameter. A screw is inserted into the indicated hole onthe test apparatus so that it sticks out a distance of approximately 2inches. The head of the screw should be smaller than the head of thenail used in the test. The sample and fixture are positioned underneaththe apparatus so that the centerlines of the nail and screw line up. Abucket is hooked to the end of the test apparatus. Weight is slowlyadded to the bucket until the test specimen fails. The weight of thebucket is measured.

Cure, End, and Edge Hardness Testing

A 0.5 inch thick sample that is 2 inches wide by 6 to 8 inches long isclamped in the vice of the testing equipment. A screw is inserted intothe indicated hole on the test apparatus so that it sticks out adistance of approximately 1.5 inches. The head of the screw should be0.235 inches in diameter. The vice and sample are positioned underneaththe test apparatus, so that the head of the screw is centered on the 0.5inch edge of the sample. A bucket is hooked to the end of the testapparatus. Weight is slowly added to the bucket until the screwpenetrates at least 0.5 inches into the sample. If the screw slips offof the side and tears through the paper, the sample is discarded and thetest is repeated.

TABLE 4 Organic Foaming Dry Cenospheres Binder Agent Water Weight Hard-Nail Run (g) (g) (g) (g) (g) Flex ness Pull Density 1 50 75 0 20 78.7330.3 10.5 2 50 75 0 20 78.73 41.6 7.9 3 50 75 0 20 78.73 24.7 7.7 4 5075 1 0 78.73 5 50 75 2 0 78.73 17.6 6 50 100 0 0 88.30 17.6 10.3 7 50100 1 0 88.30 31.3 13.6 22.6 8 50 100 1 0 88.30 16.3 6.8 9 50 100 1 088.30 19.4 6.3 10 50 100 2 0 88.30 16.6 11 50 125 0 0 97.88 22.5 8.2 1250 125 0 0 97.88 35.0 8.5 13 50 125 0 0 97.88 31.6 7.9 14 50 125 1 097.88 23.7 7.3 15 50 125 2 0 97.88 22.4 6.5 16 50 150 0 0 107.45 35.841.8 31.0 9.8 17 50 150 0 0 107.45 27.5 8.3 18 50 150 0 0 107.45 21.87.5 19 50 150 1 0 107.45 18.0 9.0 20 50 150 2 0 107.45 16.6 6.6 Dry-wallaverage of 5 tests 30.9 38.0 53.6 10.4

Example 8 Test Results II

A sample of wallboard including 50 g Extendospheres, and 2 ccsurfactant. The first type of wallboard tested included 100 g of sodiumsilicate binder mixture. The second type of wallboard tested included 75g sodium silicate binder mixture and 25 g latex binder. The test boardshad a thickness range from 0.386 inches to 0.671 inches. Testing wascompleted according to ASTM 473-3, 423, E119, and D3273-00 standards.

Flexural strength was tested and determined to be an average of 170 lbf(white side up) for the wallboard of the first type, based on threesamples. The wallboard of the second type was found to average 101 lbf(white side down), based on three samples. The highest measurement ofthe six test samples was 197 lbf. A comparative conventional gypsum wallboard was measured to be 107 lbf.

Edge hardness was determined to be an average of 15 lbf. The gypsum wallboard had an average minimum edge hardness of 11 lbf. The sample showeda 36% improvement over the gypsum sample.

Nail pull resistance was measured to be 99 lbf, based on a 3 sampleaverage. The gypsum wall board, on the other hand, measured a 77 lbf.

The thermal resistance of the sample wall board was tested. One side ofthe wall board was raised to 100° C. for two hours with no measurabletemperature increase on the cool side of the sample.

The weight of the sample was compared to the conventional gypsum andfound to be approximately 30% less than the gypsum board.

Example 9 Wallboard Formation

As another example of wallboard formation, a sodium silicate wallboardis formed by the following procedure. Sodium silicate is first foamed byadding 2 cc Steol FS 406 to 100 g sodium silicate solution (PQCorporation O binder). The mixture is placed in a 6 inch diameter paintcontainer. The mixture is mixed using a 3 inch diameter “Squirrel” mixerattached to a drill press running at 540 rpm. The operator rotates thepaint container in the opposite direction than that of the mixer. Themixture is foamed for approximately one minute and fifteen seconds. Thevolume of the sodium silicate should at least double during the foamingprocess. 50 g of Extendospheres™ (having a size of 300 to 600 microns)are added to the mixture and mixed for one more minute with the“Squirrel” mixer. The vanished mix is then poured into the mold andsmoothed with a paint stick.

Once the foamed mixture is smoothed in the mold, the mold is placed inan oven set at 85° C. The mixture is allowed to dry for approximately 12hours at this temperature.

The backing paper is added to the core after the core has driedsufficiently. A light coat of sodium silicate is painted onto the backof the paper, and the paper is placed on the core matrix. The core andpaper are covered on all sides by a polyester breather material and thenplaced in a vacuum bag. The vacuum bag is placed in an oven set at 85°C. and a vacuum is applied to the part. The part is allowed to dry for45 minutes to one hour in the oven. The finished part is then removedfrom the oven and trimmed to desired size. Various materials canoptionally be added to the core composition to accelerate drying.

Example 10 Wallboard Formation II

Another wallboard is produced according to the method in Example 9. Thecomposition of the wallboard is altered in that 75 g of sodium silicatebinder solution is used along with 25 g organic binder. The organicbinder is added to the sodium silicate binder solution along with theSteol, prior to foaming.

Example 11 Wallboard Formation III

Another wallboard is produced by first masking a mold. A base board islined with FEP. The FEP is wrapped tightly to reduce wrinkling on thesurface. Boarder pieces of the mold are wrapped with Blue Flash Tape.Killer Red Tape is used to attached to border pieces to the base pieceto form a border with an inside dimension of 14 inches by 18 inches.

500 g of microspheres (300-600 microns in size), 750 g “O” binder, 250 gorganic binder, and 20 cc foaming agent are measured and set aside. TheO binder and foaming agent are mixed using a Squirrel mixer at 540 RPMfor about 2 minutes. The organic binder is added to the mixture andmixed for an additional 30 seconds. The microspheres are slowly addedwhile mixing. When all microspheres are added, the mixture is mixed foran additional 30 seconds or until the mixture is uniform. The mixture ispoured into the mold and leveled. The mold is additionally subjected tovigorous shaking for additional leveling. The mold is placed into anoven at 100° C. and dried for 12 to 18 hours until completely dry. Paperis applied to the sample by first cutting a piece of backing paper and apiece of facing paper slightly larger than the panel. An even coat ofsodium silicate solution is applied to one side of the paper. The paperis placed on top and bottom surfaces of the panel and pressure isapplied evenly across the surface. The pressure can optionally beapplied by vacuum bagging the panel. The panel can be placed back in theoven at 100° C. for about 15 minutes until the paper is fully adhered tothe surface of the panel.

The foregoing detailed description describes the invention withreference to specific exemplary embodiments. However, it will beappreciated that various modifications and changes can be made withoutdeparting from the scope of the present invention as set forth in theappended claims. The detailed description and accompanying drawings areto be regarded as merely illustrative, rather than as restrictive, andall such modifications or changes, if any, are intended to fall withinthe scope of the present invention as described and set forth herein.

More specifically, while illustrative exemplary embodiments of theinvention have been described herein, the present invention is notlimited to these embodiments, but includes any and all embodimentshaving modifications, omissions, combinations (e.g., of aspects acrossvarious embodiments), adaptations and/or alterations as would beappreciated by those in the art based on the foregoing detaileddescription. The limitations in the claims are to be interpreted broadlybased on the language employed in the claims and not limited to examplesdescribed in the foregoing detailed description or during theprosecution of the application, which examples are to be construed asnon-exclusive. For example, in the present disclosure, the term“preferably” is non-exclusive where it is intended to mean “preferably,but not limited to.” Any steps recited in any method or process claimsmay be executed in any order and are not limited to the order presentedin the claims. Means-plus-function or step-plus-function limitationswill only be employed where for a specific claim limitation all of thefollowing conditions are present in that limitation: a) “means for” or“step for” is expressly recited; and b) a corresponding function isexpressly recited. The structure, material or acts that support themeans-plus function are expressly recited in the description herein.Accordingly, the scope of the invention should be determined solely bythe appended claims and their legal equivalents, rather than by thedescriptions and examples given above.

What is claimed and desired to be secured by Letters Patent is:
 1. Ashear panel building material comprising: a first facing membrane; asecond facing membrane; a rigid material situated between the firstfacing membrane and the second facing membrane, said rigid materialbeing self-supporting; and a core matrix disposed between said first andsecond facing membranes, said core matrix including: from about 25 wt %to about 60 wt % of microparticles based on wet formulation, from about20 wt % to about 36 wt % sodium silicate, and from about 2 wt % to about6 wt % of a vinyl acetate, wherein the rigid material is held in placewith respect to the first and second facing membranes by the corematrix.